Deal Island Impoundment
Deal Island Wildlife Management Area
Ecology and ManagementDeal Island Wildlife Management Area (13,000 acres) includes a single large impoundment (> 2500 acres) along the lower Chesapeake Bay in Somerset County, Maryland. Deal Island WMA is part of the larger Somerset-Wicomico Marshes Important Birding Area (IBA) as identified by the National Audubon Society. According to eBird, 207 bird species have been identified within the Deal Island impoundment. Among them, two Highest Priority species for Bird Conservation Region (BCR) 30, American Black Duck and Saltmarsh Sharp-tailed Sparrow, are abundant at Deal Island. Additional Priority NAWCA (North American Wetland Conservation Act) Species including: Pied-billed Grebe, Horned Grebe, American Bittern, Least Bittern, Snowy Egret, Bald Eagle, Solitary Sandpiper, Lesser Yellowlegs, Semipalmated Sandpiper, Short-billed Dowitcher, Least Tern, Short-eared Owl, and Seaside Sparrow also use the impoundment.
The original tidal marsh at Deal Island WMA was impounded in the 1960s. Between its creation and the 1990s, the impoundment was important habitat for waterfowl and wading birds. Peak numbers of waterfowl sometimes exceeded 20,000 birds. However in the mid-1990s the number and diversity of birds began to decline and submerged aquatic vegetation was much less abundant. This trend continued until 2009 when a new management regime, based around increasing the amount of SAV was implemented. The water control structures were improved. Water levels are managed to promote SAV growth. In addition, hunting days have been limited and gas motors are prohibited to reduce disturbance and prevent damage to existing SAV beds. As a result of these changes the impoundment has seen a rebound in both SAV and waterfowl.
The impoundment at Deal Island is highly vulnerable to sea-level rise and already experiences nearly weekly overtopping at the emergency spillway. In addition muskrat burrows also cause small leaks through the berm and there is some berm erosion during storm events. Despite being only 2 feet above mean high tide there have been no large scale failures in the past.
There are no visitor use studies, but staff estimate that over 100 people visit the impoundment each week for hunting, crabbing or bird watching. Deal Island WMA also cooperates with the nearby Chesapeake Bay National Estuarine Research Reserve for research on SAV and the area is used by local grade schools and colleges for educational field trips. The impoundment also buffers State Route 326, the only road connection to the rural fishing community of Deal Island, from wave energy to the south.